Speaker assembly



Oct. 2, 1962 BREISCH 3,056,857

SPEAKER ASSEMBLY Filed Dec. 27, 1961 INVENTOR.

JOHN H. BREISCH ATTORNEY United States This invention relates to music reproduction systems and more particularly to a speaker assembly for attachment to a ventilating system plenum chamber.

One of the primary objects of this invention is to provide a speaker assembly which is adaptable to mounting on the plenum chamber of a ventilating system for transmitting audio signals throughout a building by utilizing the air ducts as sound transmitting media.

The provision of such a sound system produces unusual and highly desirable effects which are audible to the ear of a listener in any of several separated rooms. Further, sound may be transmitted to various parts of a building by use of a single speaker assembly of this type, thus eliminating the necessity for an elaborate and complicated network of transmitting circuits for individual speakers in each of various rooms.

One of the desirable features in reproducing recorded music is to render the sound production non-directional and to produce the eflTect of sound emanating from several directions at one time. This may be accomplished in an ordinary home installation by attaching the speaker assembly to the ventilating system and utilizing the outlets thereof as the sound source.

Accordingly, it is an object of this invention to provide a speaker assembly which may be connected to conventional radio or amplifier systems and which may be in conjunction with a ventilating system for reproducin the sound in various rooms in a building which are produced by the radio or amplifier.

A still further object of this invention is to provide a speaker assembly having parts which facilitate the incorporation of the sound reproduction system into the ventilating system of the building.

Another important object of the invention is to provide a speaker assembly wherein the speaker mounted in a casing closes approximately eighty percent of the opening of the casing, the remaining twenty percent of the opening functioning as reflex openings to accommodate pressure changes in the casing.

Other objects and advantages more or less ancillary to the foregoing, and the manner in which all the various objects are realized, will appear in the following description, which considered in connection with the accompanying drawings sets forth the preferred embodiment of my invention.

In the drawings:

FIG. 1 is a perspective view showing the speaker assembly which is the preferred embodiment of my invention, installed in a ventilating system;

FIG. 2 is a front view of a speaker assembly;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2; and

FIG. 4 is a sectional view taken along line 44 of FIG. 2.

Referring first to FIG. 1, a speaker assembly 10, which forms the preferred embodiment of my invention, is mounted on a plenum chamber 12 of a ventilating system. The ventilating system is provided with ducts 14 which connect the plenum chamber 12 to various rooms throughout a building. The principle of transmission of sound utilized is the common speaking tube principle which accounts for the transmission of any sound waves produced in the plenum chamber 12 being conducted in practically undiminished intensity to the duct outlet irrespective of the distance from the sound source.

A permanent magnet-type speaker 16 having the usual Met voice coil connections is housed within a rectangular boxlike casing 18. The casing 18 has out-turned flanges 20 joined to the marginal edges of the side walls thereof. The casing 18 is preferably made of metal since the temperatures to which the casing 18 may be subjected are high when the plenum chamber 12 is attached to a furnace and is a part of a hot air heating system.

A perforated metallic baflle 22 is atfixed to the flanges 20 of the casing 18, effectively closing the casing for protecting the contents thereof while allowing sounds produced within the casing 18 to be transmitted therefrom.

The speaker 16 is positioned in the casing 18 in confronting relationship to the open side of the casing and the bafile 22 thereby directing the sound produced by the speaker 16 into the plenum chamber. The speaker 16 is held in abutting relationship to the baffle 22 by a resilient pad 24- formed from a material such as sponge rubber, which is disposed between the rearmost portion of the speaker and the rear wall of the casing 18. The pad 24 functions to apply continuous pressure on the speaker against the baffle 22 and also to absorb the sound waves which are transmitted rearwardly of the speaker.

The casing 18 is generally rectangular and has a size which makes the generally elliptical speaker 16 tangent at the mid-points of the sides of the casing 18. At each corner of the casing 18, an opening results between the speaker 16 and the casing 18. The total area of these open corners is approximately twenty percent of the total area of the open side of the casing 18. The open corners provide for reflex action to equalize the pressure in the casing behind the speaker cone thus obtaining speaker efficiency and fidelity.

Volume control is accomplished by a rheostat 26 which is connected across the circuit to the voice coil of the speaker 16. A pair of leads 28 are connected to the rheostat 26 and have alligator clips 30 for quick con nection to the voice coil connections on a radio or amplifier which corresponds to the voice coil connections on the speaker is. After the connections have been made to the radio and the amplifier to provide the energization for the speaker 16, the rheostat 26 may be adjusted to balance the relative intensity of the sound produced by the speaker 16 as compared with the sound produced by the speaker in the radio or amplifier.

When the speaker assembly 10 is to be installed on the plenum chamber 12, an opening is first made in the wall of the plenum chamber 12 corresponding roughly to the inside dimensions of the casing 18 surrounding the speaker 16. The speaker assembly 10 is fixed to the plenum chamber 12 by using sheet metal screws passing through the flanges 20' and the plenum chamber wall. The clips 30 are then attached to the voice coil connections on a radio or amplifier and the speaker is then operative when the said radio or amplifier is turned on. In order to balance the volume of the output from the radio and the speaker 16, the rheostat 26 is adjusted until the desired volume balance is obtained.

Having thus described this invention in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use the same, and having set forth the best mode contemplated of carrying out this invention, I state that the subject which I regard as being my invention is particularly pointed out and distinctly claimed in what is claimed, it being understood that equivalents or modifications or, or substitutions for, parts of the above specifically described embodiments of the invention may be made without departing from the scope of the invention as set forth in what is claimed.

What is claimed is:

1. A speaker assembly adapted to be attached directly 7 r 3 r to a ventilating system having an opening therein comprising a casing having an open side, flange means on said casing adjacent to said open side adapted for aflixing the speaker assembly to the marginal edges of said opening, a perforate baffle means across said opening and affixed to said flange means, a speaker in said casing disposed for projecting audible signals through said baffle means, and variable resistance means for controlling the energy to said speaker and the volume of the signal produced thereby.

2. A speaker assembly adapted to be attached directly to a ventilating system having an opening therein comprising a casing, flange means on said casing adapted for affixing the speaker assembly to the marginal edges of said opening, a perforate baflie means across said opening and aflixed to said flange means, a speaker in said casing disposed for projecting audible signals through said baflie means, a resilent sheet-like body between the said speaker and the rear wall of the casing for holding said speaker against the baffle means, variable resistance means for controlling the energy to said speaker and the volume of the signal produced thereby, and electrical connection means forming a circuit between said speaker, said variable resistance means, and a speaker circuit on a radio or amplifier.

3. A speaker assembly adapted to be attached directly to a ventilating system having an opening therein comprising a casing, flanges on said casing adapted for afiixing the speaker assembly to the marginal edges of said opening, a perforate baffle across said opening and aflixed to said flanges, a speaker in said casing disposed for projecting audible signals through said baflie, a resilient sheet-like body between the rearmost portion of said speaker and the rear wall of the casing for holding said speaker against the baflie, variable resistance means for controlling the energy to said speaker and the volume of the signal produced thereby, and electrical connection means forming a circuit between said speaker, said variable resistance means, and a speaker circuit on a radio or amplifier.

4. A speaker assembly adapted to be attached directly to a ventilating system having an opening therein comprising a rectangular casing, flange means on said casing adapted for affixing the speaker assembly to the marginal edges of said opening, a perforate baffle means across said opening and affixed to said flange means, and an oval speaker in said casing confronting said baflie means and disposed for projecting audible signals through said 'baflie means, said speaker covering eighty percent of the area of said baflle means.

References Cited in the file of this patent UNITED STATES PATENTS 

